Whats happening to my corals?

[michika]

Since upgrading to a larger tank in the beginning of September I have lost a total of 8 colonies and medium sized frags. I've also probably lost at least 7 small frags since upgrading.

Parameters have always been and continue to be
Temp 78
SG 1.025-1.026
Alk 8dkH
Ca 440ppm
Nitrate 0ppm
Nitrite 0ppm
Ammonia 0ppm
Phosphates 0.5 mg/L

We run 1x 400w 20k MH for approx 6-9 hours a day, supplimented with actinics, and 10k T5s. Tank is 77g with 75g sump/refugium. 70lbs live rock in the display tank, 5lbs in the refugium.

livestock; Lemonpeel angel, 2 blue chromis, 2 yellow chromis, lunar wrasse, regal tang, 2 tomato clowns, 1 ocellaris, signapore angel, sleeper goby, sixline wrassee, psychadelic mandarin, 1 red fromia star, 1 sand sifter, and a cleaning crew of snails, and hermits.

Corals: Frogspawn, elkhorn, zoos, cactus coral, 2 sun corals black and orange, 1 crocea clam, 1 dersa clam, neon green candy cane, and an assortment of SPS. Only my acropora seem to ever be affected. Usually whats happening is they RTN whenever I seem not to be home.

This morning something ate my clam from the bottom up, cut him free from his rock at the top of his tank, tossed him to the sandbed and ate him from the bottom up.

I am at my wits end on what to do. Everything seems fine except for my corals. Fish are all eating like piglets, water has been testing normal. I've been doing water changes bi-weekly about 10g every time. I top off with RO/DI water too. I'm also running carbon constantly, but it doesn't appear anything is making a difference.

I'm hoping to add more rock in the near future, and we'll be setting up a second 400w MH bulb this evening to complete our lighting set up. I can't even think what might be doing this, or why its happening. Please help!

[Pegasus]

As far as the clam goes, my money is on the angels.

As far as the corals go, well what can I say. My experience with Acros is that they are very sensitive animals and may not liked how they where transfered.

If I read your post right, your adding another 440 w MH to a 77 gal tank? Won't that make more than 11 w per gallon? I don't know how you are going to do this but hopefully gradually? Some say that this may be too much light.

Hope this helps

Larry

[michika]

They transfered fine. The problems didn't start until about two or three weeks after the upgrade. I doubt its the angels, as the lemon peel I've had longer then I've had corals, and the signapore has never been seen to nip or even look at my corals.

In the old tank I had 400w on a 46g, and my corals thrived. The length and depth of the tank that I have now requires 2 400w to get sufficient lighting throughout the tank. I do plan acclamate my corals slowly to the new lighting.

This is the first time in well over a year that I've had coral loss for any reason. Its just such a mystery to me.

Any ideas on chemical causes?

[Pegasus]

It's not uncommon for Angels to change their habits. You did after all change their environment and surroundings.

As far a chemical causes go, no sorry I don't. Just know that Acros can be finicky.

I assume that you transfered all the old water from the old tank therefore the addition of the new top up water shouldn't have caused that tank to recycle.
Then again...? Any amount of a spike, no matter how small, might have been enough to kill the more sensitive corals.


Larry

[michika]

Sadly there was no spike that I found, and I test once or twice a week. I've watched my tank for hours since the initial change over and I haven't seen anything from the angels that ressemble picking at the corals.

I just can't think of anything that could have caused it. There is no constant between situations as to why they are dying off. I haven't added new rock or anything that could contain hitchhikers. The only thing that has really changed is that I stopped dosing liquid reactor at night.

[vanreefer]

try checking your Ph at night... as the lack of liquid reactor at night may have changed the Ph at night...
Are there any Red Bugs on the acros?... this could be an explanation of why it is only the acros that seem to be effected

Just chucking out ideas
HTH
Dan

[michika]

The only acro that I had, which had the bugs died due to RTN almost two weeks ago. I haven't seen any bugs since. 1 coral died after the colony with the bugs was introduced, and all the ones prior, died before it was even in my system.

I do have more liquid reactor. Should I not dose tonight, test the pH and go from there. Or start with the liquid reactor again tonight?

[monza]

It might be a dumb question but whats liquid reactor?
Also as Pegasus asked, when you transfered did you use the same water or new?
Dave

[vanreefer]

I would probably check it tonight before dosing reactor and see if it's out of whack or if there is a big gap between the daytime reading and the night time one... as with everything stability is the key.
I run a lighted sump at night to reverse the Ph effect

[Funky_Fish14]

What is your daytime pH?

I cant think of anything else to add, what was suggested all does make sense. I do hope you can find the source of this problem soon!

Chris